Manufacture and production of isoprene.



UNITED STATES PATENT OFFICE.

GEORG MERLING AND HUGO KOHLER, OF EL BERFELD, GERMANY, ASSIGNORS '10FAR- BENFAIBBIKEN VORM. FRIEDB. BAYER & 00., OF ELBERFELD, GERMANY, ACOB- PORATION or GERMANY.

MANUFACTURE AND PRODUCTION OF ISOPRENE.

Specification of Letters Patent.

Patented Mar. 25, 1913.

110 Drawing. Original application filed December 8, 1911, Serial No.664,187. Divided and this application fledlarch 2, 1912. Serial No.681,284.

664,137, filed December 6,"-1911 and concerns the manufacture andproduction of isoprene by distilling with a caustic alkali or an earthalkali,- the halogen ammonium halogenidfof the formula:

t CH; CH;CH-CHCH N CH. CH: halogen halogen In order to illustrate thenew process more fully the following example is given, the parts beingby weight Manufacture and product-ion of isoprene from the tetmammom'umchlorid;

The ammonium chlorid which can be ob tained by directly combining theoxybase:

on with methyl chlorid or by converting the ammonium iodid thereof(melting point 145146 C.) with silver chlorid is a colorless,deliquescent crystal mass. It is dissolved in about 5' parts of waterand the well cooled solution is saturated with hydrobromic acid orhydrochloric acid, and heated in an autoclave on the boiling water bathfor about 24 hours. When the clear solution is evaporated on the waterbath or the water and the superfluous hydrogenhalid is separated inanothersuitable manner, the bromoor chloro-ammonium chlorid-z CHICH;GHCH(CHa)-CHg-N gg' (X-halogen) 01 remains as a thick brown syrup,which is distilled with about three times its quantity of pulverizedcaustic potash 0r soda or also with calcium or barium hydroxid with orwithoutthe addition of alcohol or water. The isoprene distils over, itis collected in a tube, cooled with ice, separated from trimethylamin bywashing it with diluted sulfuric acid, dried and'distilled. It boilsconstantly at- 34 C. The yield is nearly theoretical. c

We claim w 1. The process for producing isoprene, which rocess consistsin first heating with an alka i a halogen-ammonium-halogenid of theformula:

l CH3 CHr-CH-CH-CHr-N CH; CH; halogen halogen and secondly isolating theisoprene from the resulting mixture, substantially as described.

2. The process of producing isoprene from the halogen ammonium halogenidof the; following graphically represented formula! CH -CEL-CH-CHr-NWHQ;

halogen halogen with an alkali.

In testimony whereof we have hereunto set our hands in the presence oftwo subscribing witnesses.

GEORG MERLING. a 8.] HUGO KOHLER. [1 5.

Witnesses:

HELEN Norm, A; NUFER.

